Document Type

Thesis

Abstract

The Mesoproterozoic (1180-1030 Ma) basement complex in the central Virginia Blue Ridge consists of several mineralogically and texturally heterogeneous units. Near Crozet, Virginia, five compositionally distinct rock types occur and include: 1) layered gneiss, 2) charnockite and charnockitic gneiss, 3) biotite granitoid gneiss, 4) leucogranite, and 5) megacrystic granitoid. Two distinct foliations, including a high-temperature amphibolite to granulite facies and a low-temperature greenschist facies fabric, are variably developed in rocks with different deformation intensities. Several anastomosing northeast-southwest trending high-strain zones, including the connected Rockfish Valley and White Hall high-strain zones, cut through the basement complex. Lenses of relatively less deformed rock occur within the 1-3 km wide high-strain zones. Kinematic analysis indicates general shear with possible triclinic symmetry and apparent flattening strain. Palinspastic reconstruction of a cross-section to its undeformed state reveals 35% total shortening and less than 3 km of vertical displacement.

Date Awarded

2009

Department

Geology

Advisor 1

Christopher M. Bailey

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